Polymer mesh with reinforcing bands for skin control in hard rock mining

ABSTRACT

A polymer mesh for skin control in hard rock mining conditions is provided. The polymer mesh is manufactured using a knitted or woven design that further includes one or more pairs of solid cut-resistant bands. The bands are positioned in pairs, each band in a pair having a width of at least about 2.5″ and being generally parallel with the other band. The bands are spaced from one another at a distance of between about 1.5″ and about 4″ to create a reinforced aperture between the bands. One or more reinforcement bolts are installed within the aperture with the bands on opposing sides of each bolt buffering the edges of the steel plates associated with the bolts to prevent the plates from tearing the polymer mesh.

This application claims priority from U.S. provisional application Ser.No. 62/846,080, filed May 10, 2019.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention is related to the field of mining and, moreparticularly, to a polymer grid or mesh sheet product to cover the roofand walls of a hard rock mine or tunnel passageway for additionalsupport during material extraction operation.

Description of the Related Art

Minerals beneath the ground have been recovered through miningoperations for hundreds of years. Mining from deep shafts is madepossible through the use of reliable supports to prevent the roof stratafrom caving in upon the men and equipment working underground.

The primary means of roof support in underground mines and tunnelsincludes the use of reinforcement bolts placed in the strata.Reinforcement bolts allow the immediate roof and sidewalls around theworkers to be secured by either creating a beam effect or by providinganchorage that extends beyond areas of broken strata into structurallycompetent material. Such bolts vary in function and design and mayinclude resin glue, expansion, expansion anchor, friction, and variouscombinations thereof such as glue and expansion anchor, etc., with thetype of bolt utilized being dependent upon the kind of strata to besecured. For example, resin bolts are typically used in coal mining,while expansion bolts are utilized in tunnels and hard rock. Bolts ofthese various types are manufactured by a number of companies and arecommercially available.

Bolts in hard rock are installed using roof bolting machines or jack legdrills. As used herein in connection with the present invention and hardrock mining, the term “bolt” refers to a bolt that is inserted into thesurrounding strata to provide reinforcement and anchorage. Hard rockbolts are not considered “roof bolts” according to the meaning of thatterm as would be understood in other mining applications by those ofskill in the art.

The bolting machines are often self-propelled and allow the operator toperform drilling and bolt insertion in a hands-off method to ensuresafety. The bolting machine typically drills a hole in the strata andthen inserts a bolt into the hole. The method by which the bolt issecured within the hole is dependent upon the type of bolt beinginstalled as is known in the art.

To minimize failures in the surrounding strata, bolts are installedaccording to a predetermined pattern that must be approved by the MineSafety and Health Administration prior to mining activities. Approvalstypically dictate that bolts be installed on 3′ by 3′, 4′ by 4′, or even5′ by 5′ patterns. In addition to the bolts themselves, steel plates areaffixed to the bolts to increase bearing surface area against thestrata. The plate size is also dictated by the strata reinforcementrequirements, with typical sizes being, but not limited to, 4″ by 4″, 6″by 6″ and 8″ by 8″.

To further increase bearing surface area, many mining applicationsrequire the use of wooden header boards, steel or polymer straps, etc.,that are either anchored by one bolt or are anchored by a combination oftwo or more bolts. In addition to bolts, plates and associated hardware,many hard rock, tunneling and coal applications require further means torestrain smaller rock from falling between the bolts. The restraint ofsuch smaller rock is known in the industry as skin control. Skin controlmay take the form of welded wire mesh, chain link fencing or polymergrids or mesh sheeting products. These mesh or chain link products aresecured to the strata using the bolts.

Welded wire mesh and chain link fencing have been used exclusively inhard rock and many coal applications. However, although very strong,these products are hazardous to install, with their weight leading tomany back and shoulder injuries while their edges have resulted inlacerations.

In addition to creating problems during original installation, wire meshand chain link fencing are responsible for problems thereafter as well.Underground tunnels are very confined and, as such, equipment movingwithin the tunnels is prone to snag the welded wire or chain link panelsand bend them so that the wire extends into the passageways whereworkers are passing to and fro. Workers are often injured by these wirespuncturing and/or cutting them as they travel in these areas. Inaddition, metallic mesh has been shown to demonstrate very limited lifein acidic conditions.

To overcome these drawbacks, polymer mesh made of polyester,polypropylene, co-polymer or HDPE compounds has been used withconsiderable success. Polymer mesh not only provides extreme strengthbut is also very user-friendly as compared with steel wire.Specifically, polymer mesh is typically one seventh the weight of weldedwire mesh, is flexible, is impervious to acid and will not cut orpuncture workers if snagged by equipment.

Polymer mesh that includes solid bands to increase the strength of themesh has been used for longwall take-off screens in the coal industryfor several years. This particular mesh is made of polyester and can bemanufactured using a knitted or woven design. The bands are typicallyspaced at regular intervals such as a meter apart, with the width of thebands varying from 3″ to over 12″ depending upon the application and thestrength desired. As the bands are added for overall strengthening,their spacing along the mesh bears no particular relationship with thepositioning of the bolts.

While the use of polyester mesh is common in longwall take-off screensin coal mining, polyester mesh has not been used to any significantdegree in connection with hard rock conditions where steel plates areused in conjunction with bolts. These steel bolt plates cut or tear thepolyester mesh when force is applied to the mesh, causing the mesh tosag or break free and thereby compromising the effectiveness of the meshin maintaining skin control. This is unfortunate given the many workersafety advantages of polymer mesh.

Therefore a need exists for a polymer mesh that is resistant to beingcut and therefore suitable for durable and effective use in hard rockapplications.

SUMMARY OF THE INVENTION

In view of the foregoing, the present invention is directed to a polymermesh that provides skin control in hard rock mining conditions. Thepolymer mesh is manufactured using a knitted or woven design thatincludes a first plurality of spaced polymer strands extending in amachine direction, and a second plurality of spaced polymer strandsextending in the cross-machine direction. The second plurality ofpolymer strands intersect with the first plurality of machine directionpolymer strands in a generally perpendicular relation to create agenerally rectangular mesh opening structure. The polymer mesh ispreferably formed as a roll to be unwound and secured to the roof andside walls of the hard rock mine. Alternatively, the polymer mesh may becut into sheets and then installed.

The polymer mesh further includes at least one pair of solidcut-resistant bands or reinforcing straps that extend across the lengthor the width of the roll. As used herein, “solid” is defined as being asingle band of continuous material or as a band made of a plurality ofclosely adjacent strands that together function as an uninterruptedsingle band, similarly to the manner of fiber-reinforced tape.

Without being limited thereto, each band in the pair preferably has awidth of at least about 2.5″ and is generally parallel with the otherband. The bands are spaced from one another at a distance of at leastthe diameter of the applicable bolt. However, it is preferred that thespacing be at least about 1.5″ and up to about 4″ to provide sufficientroom to allow the hole to be drilled without having the tool catch onthe mesh, followed by placement of the bolt in the hole. The spacingthus creates a reinforced aperture between the bands with sufficientroom to allow for ease of installation. The reinforced aperture iselongated, extending along the length of the bands, and is traversed bythe polymer strands that extend in the direction transverse to thedirection of the bands, creating a plurality of segments in thereinforced aperture.

According to a preferred embodiment, the polymer mesh includes aplurality of pairs of solid cut-resistant bands, also referred to asreinforcing straps, with a spaced interval between pairs correspondingwith the spacing of the intended pattern of bolts to be installed in ahard rock mining application. The bolts with associated steel plates,which are typically square or rectangular, are used to secure thepolymer mesh to the strata, with the bolts being received within any ofthe segments within the reinforced apertures.

The width of the reinforcing straps is sufficient to ensure that aminimum of two opposed edges and all four corners of the square orrectangular steel plate used with each of the bolts rest on top of thebands. The bands are thus positioned between the steel plate and theanchoring strata and protect the mesh product from the cutting action ofthe edges and corners of the steel plates. The width of the bands issufficient so that in worst case, which can occur when the bolt ridesagainst the opposite end of the reinforced aperture and shifts the boltplate, the band is still wide enough to cover the plate edges.

The polymer mesh may be manufactured to include solid bands in themachine direction, i.e., the length of the roll; in the cross-machinedirection, i.e., the width of the roll; or in both directions. The bandsare also effective in buffering the edges of steel plates that arecircular or oblong in shape. Plate sizes may vary from about 4″ by 4″ toabout 12″ by 12″. As used herein in connection with the aperture sizeand plate sizes, “about” is intended to refer to the stated value plusor minus 1.0″. As used in connection with the width of the bands, theterm “about” is intended to refer to the stated value plus or minus0.5″. Accordingly, the width of the bands is between 2.25″ and 4.25″,but could be wider with larger size plates.

Accordingly, it is an object of the present invention to provide apolymer mesh used for skin control in hard rock mining conditions thatis manufactured using a knitted or woven design and that includes one ormore pairs of solid cut-resistant bands that extend along the length oracross the width of the roll.

Another object of the present invention is to provide a polymer mesh inaccordance with the preceding object in which each band in a pair has awidth of at least about 2.5″ to up to 4″, and possibly more, and isgenerally parallel with the other, the bands being spaced from oneanother by at least the diameter of the applicable bolt, and preferablybetween about 1.5″ and about 4″, to create an elongated reinforcedaperture for receiving a bolt having an associated steel plate.

A further object of the present invention is to provide a polymer meshin accordance with the preceding objects in which the width of the bandsis sufficient to ensure that a minimum of two opposed edges, and allfour corners, of a square or rectangular steel plate used with each ofthe bolts rest on top of the bands, the bands being positioned betweenthe steel plate and the anchoring strata and protecting the mesh productfrom the cutting action of the edges and corners of the steel plates.

Yet another object of the present invention is to provide a polymer meshin accordance with the preceding objects in which the polymer meshincludes a plurality of pairs of solid cut-resistant bands with a spacedinterval between the pairs corresponding with the spacing of theintended pattern of bolts to be installed in a hard rock miningapplication.

Still another object of the present invention is to provide a polymermesh in accordance with the preceding objects in which the solid bandsare manufactured in the machine direction, in the cross-machinedirection, or in both directions.

A further object of the present invention is to provide a polymer meshin accordance with the preceding objects in which the reinforcedaperture is effective to buffer the edges of steel plates sized betweenabout 4″ by 4″ to about 12″ by 12″, and is also effective in bufferingthe edges and corners of steel plates that are circular or oblong inshape.

Yet a further object of the present invention is to provide a polymermesh in accordance with the preceding objects in which the polymer meshis formed into a roll that is unwound while being installed in a hardrock mining application or is cut into sheets and then installed.

Another object of the present invention is to provide a polymer mesh forbeing secured to a mine strata for skin control, the polymer mesh havingreinforcing straps that are sized and spaced along the polymer meshaccording to the size of the plates and bolts to be used to install thepolymer mesh and support the mine strata.

Yet another object of the present invention is to provide a polymer meshin accordance with the preceding objects that is cost-effective tomanufacture, user-friendly to handle and install, and effective incontaining small rocks and strata while resisting cutting and tearingfor improved safety in a hard rock mine.

These together with other objects and advantages which will becomesubsequently apparent reside in the details of construction andoperation as more fully hereinafter described and claimed, referencebeing had to the accompanying drawings forming a part hereof, whereinlike numerals refer to like parts throughout.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of a polymer mesh with solid cut-resistant bandsfor hard rock mining in accordance with the present invention.

FIG. 2 shows a roll of a polymer mesh having four pairs for solid bandsextending in the machine direction in accordance with the presentinvention.

FIG. 3 shows a roll of a polymer mesh having three pairs of solid bandsextending in the machine direction in accordance with the presentinvention.

FIG. 4 is a cross-sectional view of a mine tunnel having a roof and sidewalls to which two rolls of the polymer mesh shown in FIG. 1 have beenaffixed with bolts.

FIG. 5 is a plan view of the polymer mesh as secured to a mine stratausing a bolt with a steel plate having two opposed sides buffered by asolid band.

FIG. 6 is a plan view of a polymer mesh having solid cut-resistant bandsarranged in groups of three according to a second embodiment of thepresent invention.

FIG. 7 shows test conditions for Tests 1-4 used in developing thepolymer mesh according to the present invention.

FIGS. 8A and 8B illustrate the start and finish of Test 1, respectively.

FIG. 8C is a graph of the load (lbf) versus displacement (in) results ofTest 1.

FIGS. 9A and 9B illustrate the start and finish of Test 2, respectively.

FIG. 9C is a graph of the load (lbf) versus displacement (in) results ofTest 2.

FIGS. 9D and 9E illustrate the reinforcing band after the completion ofTest 2.

FIGS. 10A and 10B illustrate the start and finish of Test 3,respectively.

FIG. 10C is a graph of the load (lbf) versus displacement (in) resultsof Test 3.

FIGS. 11A and 11B illustrate the start and finish of Test 4,respectively.

FIG. 11C is a graph of the load (lbf) versus displacement (in) resultsof Test 4.

FIGS. 11D and 11E illustrate the reinforcing band after the completionof Test 4.

FIGS. 12A and 12B illustrate the start and finish, respectively, of achain link fencing test.

FIG. 12C is a graph of the load (lbf) versus displacement (in) resultsof the chain link fencing test as shown in FIG. 12B.

FIG. 13 is a graph comparing the test results obtained in Tests 1-4 ofthe polymer mesh of the present invention against that of the chain linkfencing.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

It is to be understood that the embodiments described herein aredisclosed by way of illustration only. It is not intended that theinvention be limited in its scope to the details of construction andarrangement of components set forth in the following description orillustrated in the drawings. Also, in describing the preferredembodiments, specific terminology will be resorted to for the sake ofclarity. It is to be understood that each specific term includes alltechnical equivalents which operate in a similar manner to accomplish asimilar purpose.

As shown in FIG. 1, the present invention is directed to a polymer meshgenerally designated by reference numeral 10. As shown in FIGS. 2 and 3,the polymer mesh 10 is formed as a roll 12 to be unrolled and secured toa mine roof for skin control, particularly in a hard rock mine.

The polymer mesh includes a first plurality of polymer strands 14 thatextend in a machine direction, and a second plurality of strands 16 thatextend in the cross-machine direction. The first plurality of polymerstrands are spaced from and substantially parallel with one another.Similarly, the second plurality of polymer strands are spaced from andsubstantially parallel with one another. The second plurality of polymerstrands intersect with the first plurality of machine direction polymerstrands in a generally perpendicular relation to create a mesh structurehaving generally square or rectangular mesh openings 18, as shown inFIG. 1. As used herein, “substantially parallel” refers to anarrangement that the skilled person would recognize as parallel innature but not with mathematical precision. Similarly, openings that are“generally square or rectangular”, and strands that are in a “generallyperpendicular relation” refer to arrangements that the skilled personwould recognize as corresponding to the indicated shape or relation butwithout requiring mathematical precision in such shapes and relations.

According to the present invention, the polymer mesh 10 includes atleast one pair of solid cut-resistant bands generally designated byreference numeral 20. As shown in FIGS. 1-3, the solid bands 20 have alength that extends in the machine direction 22. However, the polymermesh 10 may be manufactured with the solid bands (not shown) extendingin the cross-machine direction 24 or with solid bands that extend inboth the machine and cross-machine directions. Whether extending ineither or both directions, the solid bands have a width of at leastabout 2.5″ to buffer the edges and corners of the steel plates that areused with bolts to secure the polymer mesh 10 and provide support to theroof and side walls in a hard rock mining application as will be furtherdiscussed hereinafter.

As shown in FIG. 1, a plurality of pairs of solid bands 20 are spacedabout 4 feet from one another for a 4 foot bolting pattern. As usedherein in connection with spacing between pairs of bands, the word“about” refers to the stated value plus or minus 0.5 ft. The bands ineach pair are substantially parallel with one another and separated by adistance of at least the diameter of the intended bolt, and preferablybetween about 1.5″ and about 4″, as measured from the inner edge of oneband to the inner edge of the other band in the pair, and morepreferably about 2.5″, to create a reinforced aperture, generallydesignated by reference numeral 26, between the bands. The reinforcedaperture is elongated, extending along the length of the bands, and istraversed by the polymer strands 16 that extend in the cross-machinedirection, creating a plurality of generally rectangular segments 27 inthe reinforced aperture 26. A bolt may be installed within any of thesesegments of the reinforced aperture.

It should be noted that as the reinforced aperture increases in lengthand width, the width of the solid band must also be increased to ensuredirect contact with the edges and corners of the steel plates.Therefore, upon selecting a band spacing and resulting reinforcedaperture size from within the range of values provided herein, the widthof the bands must be adjusted to ensure that the band is wide enough tocover the plate edges and corners even if the bolt rides against theopposite end of the reinforced aperture and creates a correspondingshift in the position of the bolt plate.

In a hard rock mine, the bolts are installed with associated plateswhich are typically rectangular and made of steel. FIG. 4 shows arepresentative cross sectional view of a mine tunnel, generallydesignated by reference numeral 100, having a roof 102 and side walls104 to which two panels of the polymer mesh 10 have been affixed withbolts 106 having steel plates 108 to secure the roof and side walls ofthe mine. The bands 20 are manufactured with sufficient width to ensurethat a minimum of two edges and all four corners of the square orrectangular steel plate 108 used with each of the bolts 106 rest on topof the bands 20 as shown in FIG. 5. The bands are thus positionedbetween the steel plate and the anchoring strata and protect the meshproduct from the cutting action of the steel plates as shown in FIG. 4.

As also shown in FIG. 4, the polymer mesh may be installed with tworolls that overlap, or with cut sheets that overlap, in order to coverthe desired area. In this overlapped configuration, the solid bands addsignificant reinforcement and cut resistance. According to onearrangement, the bands of the overlapping mesh are positioned to rest ontop of the bottom mesh and then the bolt is inserted through theoverlapped reinforced apertures of the top and bottom mesh layers. Theresult is that the seam or overlapped portion has even greater strengththan the single mesh layer portions of the installed polymer mesh.

FIG. 6 illustrates a polymer mesh layout having solid bands 20 in groupsof three to define two elongated apertures per band group according to asecond embodiment of the present invention. The polymer strands of theunderlying mesh that extend in the machine and cross-machine directionsare not shown for greater clarity in illustration of the solid bands 20.The bands are about 3″ wide and are spaced from one another by about2.5″. Bolts may be installed within either of the elongated apertures 26created by the three grouped bands as shown. This arrangement, in whichthe band groups have a spacing center-to-center of about 4 feet, for a 4foot by 4 foot bolting pattern, is suitable for use with 6″ by 6″ steelplates.

The effectiveness of the solid cut-resistant bands was confirmed througha series of tests that were conducted at NIOSH Spokane in January 2019.The test conditions included a domed ram head 30 having a 24″ total ramstroke, concrete reaction columns 32, a 1,500 kN jack 34 positioned atopa reaction floor 36, rock bolts 38, and load bolts 40, as shown in FIG.7. The ram head 30 was roughly even with the tops of the columns 32 asshown. Product samples 42 were restrained on top of the ram head in itslowered position using four D-bolts at 4″ spacing with 6″ bolt boardsand 6″ square plywood boards having a center hole to receive the boltand referred to in the text associated with FIGS. 7, 8A, 8B, 9A, 9B,10A, 10B, 11A, and 11B as “holy boards”. The holy boards were usedduring testing to keep the polymer grid from slipping so an accuratestrength test could be performed. Following upward movement of the ramhead, the displacement of the product sample was measured.

In Test 1, referred to as the “200 by 200 Wood” test and having a singleboard, the installation sequence for the product sample was 1) holyboard; 2) mesh; and 3) bolt plate. All four bolts 38 were placed outsideof the solid bands 20, referred to in the test data as reinforcingstraps. The peak load was 4315 lbf, displacement at peak load was 9.7inches, and maximum displacement was 19.5 inches. Illustrations showingthe start and finish of Test 1 are set forth in FIGS. 8A and 8B,respectively. A graph of the load (lbf) versus displacement (in) for the200 by 200 Wood test is shown in FIG. 8C.

In Test 2, referred to as the “200 by 200 Doublewood” test and havingtwo boards, the installation sequence for the product sample was 1) holyboard; 2) mesh; 3) holy board; and 4) bolt plate. Two bolts 38 wereplaced outside of the reinforcing strap 20 with the mesh double-foldedunderneath, and two bolts 38 were placed inside the reinforcing strap 20(see FIG. 9A). The peak load was 17465 lbf, displacement at peak loadwas 13.5 inches, and maximum displacement was 18.1 inches. Illustrationsshowing the start and finish of Test 2 are set forth in FIGS. 9A and 9B,respectively. A graph of the load (lbf) versus displacement (in) for the200 by 200 Doublewood test is shown in FIG. 9C. Illustrations of thestrap performance at the conclusion of Test 2 are provided in FIGS. 9Dand 9E.

In Test 3, referred to as the “200 by 200 Midstrap” test, theinstallation sequence for the product sample was 1) holy board; 2) mesh;and 3) bolt plate. Two bolts 38 were placed outside of the reinforcingstrap 20 with the mesh double-folded underneath, and two bolts 38 wereplaced through the reinforcing strap 20. The peak load was 9045 lbf,displacement at peak load was 12.8 inches, and maximum displacement was18.3 inches. Illustrations showing the start and finish of Test 3 areset forth in FIGS. 10A and 10B, respectively. A graph of the load (lbf)versus displacement (in) for the 200 by 200 Midstrap test is shown inFIG. 10C.

In Test 4, referred to as the “200 by 200 Midstrap Doublewood” test, theinstallation sequence for the product sample was 1) holy board; 2) mesh;3) holy board; and 4) bolt plate. Two bolts 38 were placed outside ofthe reinforcing strap 20 with the mesh double-folded underneath, and twobolts 38 were placed through the reinforcing strap 20. The peak load was17670 lbf, displacement at peak load was 13.2 inches, and maximumdisplacement was 18.4 inches. Illustrations showing the start and finishof Test 4 are set forth in FIGS. 11A and 11B, respectively. A graph ofthe load (lbf) versus displacement (in) for the 200 by 200 MidstrapDoublewood test is shown in FIG. 11C. Illustrations of the strapperformance at the conclusion of Test 4 are provided in FIGS. 11D and11E.

In addition to the polymer mesh tests, a chain-link fencing test with2-inch aperture and 9 gauge wire was also conducted. For the chain-linkfencing test, the installation sequence was 1) mesh; and 2) bolt plate.Each bolt 38 was placed equidistant from each corner of a 6′ by 6′chain-link fence sample 48. The peak load was 17640 lbf, displacement atpeak load was 18.1 inches, and maximum displacement was 21.5 inches.Illustrations showing the start and finish of the chain-link fencingtest are set forth in FIGS. 12A and 12B, respectively. A graph of theload (lbf) versus displacement (in) of the chain-link fencing test isshown in FIG. 12C.

FIG. 13 is a graph comparing the test results obtained in Tests 1-4 ofthe polymer mesh with reinforcing straps of the present inventionagainst that of the chain-link fencing. As shown, the performance of thesolid bands according to the present invention was comparable orsuperior to that of chain-link fencing when the bolts are positionedinside or through the reinforcing straps.

To summarize the results of Tests 1-4:

-   -   1) The mesh straps did not break during the testing.    -   2) Failures that occurred were due to stripping of the material        at the bolt plate (see FIG. 8B).    -   3) The solid bands made a significant difference in the        toughness around the bolt plate as far as resistance to        stripping as well as cutting (see FIGS. 9D, 9E, 11D and 11E).    -   4) The bands were not cut by the bolt plate on the inner side        toward the dome.    -   5) Doubling the mesh material over upon itself simulated a solid        strap.    -   6) With no strap breakage, the 200×200 kn 2.5″ pattern proved        effective as a base material.

The polymer mesh according to the present invention can be made ofpolyester, polypropylene, co-polymer or HDPE compounds, eitherflame-retardant or non-flame-retardant. The polymer mesh may bemanufactured using a knitted or woven design, knotted mesh, or any othersuitable method of producing a mesh configuration. The strength range ofthe mesh may range from between 80 kn/m² by 80 kn/m² to up to 400 kn/m²by 400 kn/m². The unit kn/m² is a strength measurement that can beconverted into lbs/ft, with there being 68.5 lbs/ft for every kn/m².Therefore, 80 kn/m² is equal to 5480 lbs/ft.

In addition, as an alternative construction the reinforced polymer meshaccording to the present invention may be made with single bandsprovided the bands are of sufficient width to buffer the edges andcorners of the steel plates in the manner as has been described herein.With such single bands, the mesh may be manufactured with pre-placedholes properly spaced for the bolts, or the user may create the holes bycutting or burning. However, while it is possible, this alternativeembodiment is not preferred.

The foregoing descriptions and drawings should be considered asillustrative only of the principles of the invention. The invention maybe configured in a variety of shapes and sizes and is not limited by thedimensions of the preferred embodiment. Numerous applications of thepresent invention will readily occur to those skilled in the art.Therefore, it is not desired to limit the invention to the specificexamples disclosed or the exact construction and operation shown anddescribed. Rather, all suitable modifications and equivalents may beresorted to, falling within the scope of the invention.

What is claimed is:
 1. A polymer mesh for securing to a mine strata forskin control, said polymer mesh comprising: a plurality of polymerstrands spaced from and substantially parallel with one anotherextending in a machine direction; a plurality of polymer strands spacedfrom and substantially parallel with one another extending in across-machine direction and intersecting the plurality of machinedirection polymer strands to create a mesh structure; and at least onepair of substantially parallel solid bands having a length that extendsin one of the machine and cross-machine directions, each of the solidbands having a width of at least about 2.5 inches, the pair of solidbands being separated by a distance of at least the diameter of anapplicable bolt to create an elongated reinforced aperture between thebands, said reinforced aperture being traversed by the plurality ofpolymer strands that run transverse to the direction of the bands. 2.The polymer mesh as set forth in claim 1, wherein the pair of solidbands are substantially parallel and separated from one another by adistance of between about 1.5 inches and about 4 inches.
 3. The polymermesh as set forth in claim 1, wherein the solid bands extend in themachine direction, said reinforced aperture being traversed by theplurality of polymer strands that extend in the cross-machine direction.4. The polymer mesh as set forth in claim 1, wherein the solid bandsextend in the cross-machine direction, said reinforced aperture beingtraversed by the plurality of polymer strands that extend in the machinedirection.
 5. The polymer mesh as set forth in claim 1, wherein thesolid bands extend in both the machine direction and the cross-machinedirection.
 6. The polymer mesh as set forth in claim 1, wherein thesolid bands are made in a single process with the polymer strands. 7.The polymer mesh as set forth in claim 3, wherein said polymer meshincludes at least a first pair of bands and a second pair of bands thatare substantially parallel with one another, each band having a width ofat least about 2.5 inches, with the bands in a given pair beingseparated by a distance of between about 1.5 inches and about 4 inchesto create a reinforced aperture defined by each pair, said first andsecond pairs of bands being spaced about 4 feet apart.
 8. The polymermesh as set forth in claim 1, wherein the pair of solid bands is furtherassociated with a third band to create two elongated reinforcedapertures, a first elongated aperture between the pair of bands and asecond elongated aperture between one band of the pair and the thirdband.
 9. The polymer mesh as set forth in claim 8, wherein the thirdband is separated from the one band of the pair by a distance of betweenabout 1.5 inches and about 4 inches.
 10. The polymer mesh as set forthin claim 1, wherein the polymer mesh is formed as a roll and isinstalled by unrolling the roll during installation or by cutting theroll into sheets which are then installed.
 11. A polymer mesh formed asa roll to be secured to a mine roof or side wall for skin control, saidpolymer mesh comprising: a plurality of polymer strands spaced from andsubstantially parallel with one another extending in a machinedirection; a plurality of polymer strands spaced from and substantiallyparallel with one another extending in a cross-machine direction andintersecting the plurality of machine direction polymer strands tocreate a mesh structure; and a plurality of pairs of solid reinforcingbands in spaced relationship in one of the machine and cross-machinedirections, each of the solid reinforcing bands in the plurality ofpairs having a width of at least about 2.5 inches, and a spaced intervalbetween pairs corresponding with a bolt pattern spacing for installingthe polymer mesh and securing a roof or side wall in a hard rock miningapplication.
 12. The polymer mesh as set forth in claim 11, wherein eachband in a pair is substantially parallel with the other band in saidpair and separated therefrom by a distance of between about 1.5 inchesand about 4 inches to create an elongated reinforced aperture betweenthe bands, said reinforced aperture being traversed by the plurality ofpolymer strands that run transverse to the direction of the bands. 13.The polymer mesh as set forth in claim 12, wherein the reinforcing bandsare made of polyester, polypropylene, co-polymer or HDPE compounds in asingle process with the polymer strands.
 14. A polymer mesh for securingin a mine strata for skin control with bolts and associated steelplates, said polymer mesh comprising: a plurality of polymer strandsspaced from and substantially parallel with one another extending in amachine direction; a plurality of polymer strands spaced from andsubstantially parallel with one another extending in a cross-machinedirection and intersecting the plurality of machine direction polymerstrands to create a mesh structure; and at least one pair ofsubstantially parallel solid bands having a length that extends in oneof the machine and cross-machine directions, the pair of solid bandseach having a width of at least about 2.5 inches and being separated bya distance sized to accommodate a size of the associated steel platessuch that at least two opposed sides of said plates rest on top of thebands.
 15. The polymer mesh as set forth in claim 14, wherein the platesare generally rectangular and all four corners of the plates also reston top of the bands.